Portable arc-welding apparatus



May 6 1924.

1,493,440 R. STRESAU PORTABLE ARC WELDING APPARATUS Y Filed Nov. 20, 1920 2 Sheets-Sheet l 32 27- .26 2@ M? MH www" 20. 1920 2 Sheets-Sheet 2 I Il 4 l ATTORNEY May 6 1924.

Filed Nov.

R STRESAU PORTABLE ARC WELDING APPARATUS IIIIIIH ".Illlllll WITNESS Patented May '6,.1-924.

UNITED STATES PATENT oFFlc'E'.

RICHARD STRIESAU, OF.WAUWATOSA, WISCONSIN, ASSIGNOR TO A. O. SMITH COB-- '.POBATION, OF MILWAUKEE, WISCONSIN, A CORPORATION 0F NEW YORK.

Ion'rAnnn' Anc-WELnIne APPARATUS.

Application led November 2Q, 1920. Serial No.-425,380.

To all/whom t may concern: y

' Be it known that I, RICHARD S'rnEsAU, a ,citizen of the United States, residing in the v city of Wauwatosa, county of Milwaukee and 5 State of Wisconsin, have invented a certain new and useful Improvement in Portable Arc-Welding Apparatus; and I do declare the following to be a clear', exact, and complete description thereof, such as will enable 1C persons skilled in the art to which the invention pertains to make and use the same, reference being had to the accompanying drawings as showing one orm of constructionin which my mvention has been embodied.

My invention-relates to the art of electric arc Welding. i Y

The invention, in its-present embodiment, comprises a portable Welding apparatus, which has been especially designed for general use in Welding' small parts. However, the principles of construction and operation residing in my present apparatus are such that the invention embodied therein is applicable to other classes of welding, as Well as to heavier machines. v

The invention resides in a construction in which the Welding arc isstruck by the autod matic Withdrawal of the fusible metallic 3o weldrod from its point of contact with the "Work to be welded. The said VWeldrod, which transmits the welding current, is withdrawn to strike the arc through the energization of an electro magnet, which latter is Within the welding circuit and which is excited'as the point of the weldrod is brought into the described contact. The making of such contact serves also to close the break existing in the welding circuit, and to establish the welding current through the electro magnet and'the fusible weldrod.

The invention also resides in a construction in which the devic actuated by the magnet and employed for withdrawing the weldrod to strike the are, are also utilized as a means to feed the weldrod to the work in the ratio of the consumption of sich vveldrod, during the time that the welding current is flowing and as the welding proceeds.

The invention furtherA resides in means herein shown as a pairkof rollers which withdraw the weldrod to strike the welding arc and, in connection therewith, deviceswhich operate through vthe said means to reverse the direction of movement of the weldrod and feed the latter to the Welding line in the ratio of the fusion of the Weldrod.

A small electric motor, mounted upon and constituting part of the portable apparatus, A

drives the devices for feeding the weldrod. Means have also been provided for rendering inoperative the-devices for feeding the Jfusible Weldrod when the latter has been consumed Within the prescribed limits.

Means have also been provided for maintaining the engagement of the feeding meansv with the Weldrod, in certain cases, after such feeding means have been brought into position for operation through the action of the electromagnet.

The term Weldrod, Las used arbitrarily in the specification and claims of this case, is intended to a ply to that type of electric current con uctor formed as a metallic Wire, of definite or indefinite length, which is progressively Jfused and completely consumed as the Welding operation proceeds, by the metallic electric arc formed between the free endA or point of the Wire and the work upon which the welding is then being performed. In such Welding operation, the

.wire constituting the weldrod is completely reduced by the heat generated in the electric arc, in the ratio of the feeding movement of the weldrod toward the workand the molten metal flowing rom the weldrod is deposited at and incorporated in the joint as additionalwelding material, thereby increasing the resistance of the joint to the tensile stresses to which it may be subjected. At the same time, the local areas of the parts to be Welded are brought to a proper that a homogeneous weld' is produced by the union of the metals. A distinction is thus made 'between the destructible weldrod and the usual carbon pencil or other form .state of fusion by the action of the arc, s0

of .current carrying electrode, which latter does not contribute-additional Welding material to the welded joint. The present invention constitutes an improvement vupon the arc welding a aratus in my application filed uly 17 1920, serial No. 396,881, and which Since the filing hereof has matured into Patent N o. 1,407,900, granted February 28, 1922.

The novel features of my invention will be pointed ut in the appended clalms.

In the drawings which accompany thisl specification.

l Figure 1 is a plan view showing the genmeans for releasing the said carrier sothat `the latter may be free to feed the weldrod, under the operation of the weldrod feeding devices.

Fig. 4 is a general view in elevation, of the welding mechanism, thedetails of which will be disclosed hereinafter.

Fig. 5 is a view from the right of Fig. 4, drawn to the same scale, but partly broken out, showing the relative arrangementl of the driving motor and some other parts.

Fig. 6 is a diagrammatic view showing the wiring connections of the apparatus.

Fig. 77 is a diagrammatic view showingv the movement of the weldrod feeding devices in withdrawing the weldrod to `establish the arc.

Fig. 8 is a similar view-showing the adaptation of the invention to use in connection with a continuous weldrod.

. Referring to the drawings, which merely show but 'one embodiment of my invention, Figure 1, the fixed pivot post or stud 10h-as adjustably mounted thereon a radial arm 11,

`to the free arm of which is pivotally attached one end of a. rod 12, uponthe other end of which t'he welding apparatus or head is secured by a clamp 13, or other means, which will permit the desired .radial \or longitudinal adjustment with relation to the supportingv rod 12. The clamp 13 is attached to a frame 14, which latter with the elements supported thereby constitute thev .welding apparatus or head. The welding head, while movable in an operating plane which is parallelor substantially so with respect to the welding line, is relatively stationary with regardto the work to be welded, so as to maintain the constancy of the arc during the progress of Weldin A weldrod carrier 15 is guide for vertical or angular movement upon the front of the frame 14, such angular movement depending upon the radial adjustment ofthe 1,4es,44o

front side of the frame. In the construction shown, the rollers 17 are in vertical alignment, and the weldrod carrier is maintained in the grooves of the said pulleys 17 by means of a grooved feeding roller 18, supported upon the opposite side ofthe path of movement of the weldrod carrier, and bearing against the said carrier at a point between the grooved rollers 17.

The said grooved'roller 18v is fixed to a shaft 19, rotating in bearings formed in a frame 20, pivoted to the franie 14, and which frame 20 with the roller 18 works in an opening in the said frame 14. The piv- .oted frame 20 is provided with an arm 21, extending through the said opening, and ,actuated in one direction to engage the roller 18 with the weldrod carrier, by the force of an expansion spring 22, Fig. 3, conined by a bracket 23 upon the rear of the frame 14. At its outer end the shaft 19 is provided with an insulatedhand wheel 24, by the turning of which the weldrod carrier may be caused to have vertical reciproea-A A tion, due to the frictiona'l engagement of the grooved roller 18 therewith. Thus the weldrod 25, supported by the carrier 15, may be caused to approach the work to be welded to position the point of the weldrod in relation thereto, o1` to be withdrawn therefrom, as may be necessary when it is desired to insert a fresh weldrod in the carrier. The weldrod carrier is notched or shouldered, as at 26, for the reception of the bent end 27, of a lever 28 pivoted at its upper end to the bracket 23, and working in the opening in the frame 14, before referred to. The lower end of the lever 28 is provided with apin 29, which works in a slot formed in the bracket support-ing the lower guiding roller 17 Thepurpose in providling the lshoulder 26 for engagement by t'he end 27 of the lever 28,lis to enable the weldrod carrier 15 to be maintained in elevated Y position when it becomes necessary to insert a fresh weldrod.

Coincidently with the rotation of the hand wheel 24, to'impart a downwardv movement to the weldrod carrier 15, to bring the point of the weldrod linto contact with the work to strike an arc and establish the/welding circuit, disengagement of the ,/lever 28 from the shoulder 26 of the said carrier, is

effected by means of a pointed cam wheel 30, fixed upon the shaft 19, the points of such cam wheel acting upon a wear plate 31, formedupon the lever 28.

The weldrod :carrier 15 is provided at its Y nector of holder 33 is bored for the, reception lower end with an insulated coupling 32, which in turn is provided at its other end with a connector or holder 33, through which the welding current is transmitted by means of connection 34. The lower end of the conof the bare end of the metallic weldrod 25, and secured therein'by means of a thumbscrew, and as now commonly practiced in the electric welding art.

A bracket 35,p attached to the rear of the frame 14, supports a small constantly driven electric motor 36, which through suitable pulleys and connecting belt 37, or other means, drives a worm 38 fixed upon a shaft journalled in bearings on the frame 14.

`The gudgeons 'of the grooved rollers 39 and 40, which have as one of their functions that of feeding the weldrod, are journalled in the free ends of floating links 41 and 42, which are attached to the lower arms of levers 43 and 44, pivotally mounted between their ends uponl the frame 14. The worm 38, previously referred to, drives a worm gear 45, rotating fabout a flXed'point on the frame 14. A pinion 46 attached to the gear 45 is `in engagement with a gear 47 mounted to rotate upon the pivot of the arm 43. A reducing pinion 48, mounted toV rotate with the gear 47, engages an idler v49 mounted to rotate upon the pivotal connection between the link 41 and the lever 43. The idler 49 is in engagementY with a gear 50, rotating with the vgrooved roller 39, so that when the groovedrollers 39 and 40 are brought into frictional engagement with the weldrod car? rier l5, the latter will be fed down throu h the operation of the motor 36, through t e rotation of the said rollers 39 and 40, the former of which is constantly driven.

An electro magnet 51 is supported uponv an extension 52 of the frame 14,*and isadapted to attract the armature y53, when the coilsof the magnet are energized by the passing of an electric lcurrent therethrough,in the present instance, the weld'- ing current. Ifhe said armature'is provided with a hub 54, from which extends a bar 55. The armature "53, through the bar 55,. is supported in space `at the free ends vof parallel levers 56 and 57 pivotallymounted 4on the franie 14. The mannerofconnecting thebar 55'ofthe armature't'o the' supporting levers 56 and 57 insures a.para1.

ll'V motion of the armature' under the 1 inlfe'nce of the magnetic attraction created l *iii-:the coil. .The lever 57 referred to may be.

provided 'with a branclr\ 58, to the free end of which is ,connecteda link 59, the

' other end ofl which is connectedto the floating' ivot off'the feedingvrller" 39. A second ink 60l is likewiseconnected to the free end of arm'58 vof the lever 57, and at its other end to one arm of a bell crank lever 61,

pivoted uponthe frame 14. The other arm '51, and energizing the latter.

of the bell crank is connected by means of a crank 62 to the floating pivot of the grooved roller 40.

Set screws 63, passing through lugs formed upon the frame 14, and bearing upon the outer faces of the upper arms of levers 43 and 44, are adapted to limit the approach of "'fze grooved feeding rollers 39 and 40, whey. such limit is not determined by the presence of the weldrod carrier l5 therebetween. Suitable fined between the opposite sides of the upper ends of levers 43 and 44 and regulating screws 65, will through their compression, enable the armature 53 to receive its full movement under attraction by the electro magnet 51, and through their expansion will cause the feeding rollers 39 and 40 to engage the weldrod carrier 15 with a degree of friction which will act as a positive feed to the said carrier, as the said`rollers 39 and 40 are rotated. lThe said springs will also compensate for any irregularities of movement which' may occur in the passage of the weldrod carrier 15 between the rollers springs 64 con- 39 and'40, without impairing such frictional the welding circuit 75. rlhe weldrod carrier will be caused to descend by lthe rotation of the hand wheel 24, until the point of the weldrod is brought into contact with the workto be welded, and which is within the welding circuit.` Upon such contact being made, the circuit is completed and the welding current is established, such current, as before stated, traversing the electro magnet The magnetic attraction thus created will draw the armature 53, and through the links and levers connected to and operated by the bar 55 of the armature,'will swing the grooved feeding rollers 39 and 40 upwardly and toward each other, and into gripping engagement with the weldrod carrier 15, to

withdraw the point of the-weldrod from contact with the work and strike the welding "arc. The motor 36, which is running the while, through the intermediate v.gearing previously described, will now transmit-the `rotating vmovement of the grooved rollers 39 and 40, to the weldrod carrier 15, so as to .-impart a reverse or feeding movement A' thereto.

The distance through which the grooved rollers 39 and 40 move in withdrawing the weldrod will be such as to establish a welding arc of appropriate length, and which latter will be maintained as the fusible weldrod is fed to the work. By the operation of the device as described, the arc between the weldrod and the work isy automatically established. and coincidentally therewith the fusing of the weldrod and the forward feeding of the latter take place as the welding proceeds. vWithin the limits of the construction illustrated, and as described, the feeding of the weldrod and the fusing thereof will be continued until the weldrod is consumed. The work to he welded will be arranged in a plane approximately parallel'to the path of movement of the welding head thereon, s0 that an arc of constant value will be maintained.

To insure the engagement of the feeding rollers 39 and 4() with the weldrod carrier 15, in case an alternating current isvused for welding, I may employ a locking device, which vmay he in the form of a lever 70, Fig. 2, pivoted to the frame 14, and bearing with one end ragainst the huh 54 of the armature. The' other end of the lever-70 is counected t0 a latching device 71, adapted to he engaged bv a stop 72 upon the frame 14. By pulling upon the connection between the latching device and the lever 70. the. latter will be rotated soas to engagethe hub 54 of the armature 53 and prevent the outward movement thereof under the weight of the parts associated with the feeding rollers "39 and 40. when the alternating current crosses the zero` line. But the latching device need not be used when a direct current is employed for welding.

In order to prevent the further feeding of the weldrod as the latter reachesa predetermined stateof consumption, I form a circumferential depression 73 about the upper end of the weldrod carrier 15, into which depression the rollers 39 and 40 may pass and be restrained from further feeding engagement with the carrier 15, by means of set screws 63 above described. I also provide a stop pin 74 in the upper end of the said carrier, which stoppin is adapted to he brought into engagement with the guide '16 upon the frame 14. andthus arrest the downward movementv f the weldrod carrier, and prevent further movelnent thereof, when the feeding `rollers 39 and 40 pass into the depression 73.; l

As indicated diagrammatically in Fig. 7, thc arcs through which the feeding rollers 39 and 40 pass in their upward movement will be so proportioned as to withdraw the point of the weldrod from its contact with the work and strike a welding arc of suitable, length when the welding circuit is completed. The l.operation of thus withdrawing the weldrod for the purpose of striking an arc between its fusing endandthe work to be welded, is not.l however, limited in its application to use in connection wit-h weldrods of short lengths. The operation may be employed in connection with continuous weldrods, which, as is now known in this art, involves the use of weldrod Inaterial drawn from a reel, about which a'v weldrod ofexceeding length is coiled.'l In making application of the invention in thev manner last described` it is arranged that the coil supporting the continuous weldrod be placed somewhat at one side of the line of travel of the weldrod, in order that the length .of weldrod between the coil and the feeding' rollers may be displaced in a vertical direction, hy reason of'its flexibility i without encountering the resistance whichv exists if a direct thrust in withdrawing the weldrod to establish the arc is made. The operation is indicated in Fig. 8, in which thedotted line l'indicated the freedom of movement referred to, when the weldrod is withdrawn to establish the are. between the point thereof and the work to be welded.

The initial movement of the normally separated rollers 39 and 40through converging arcuate paths ceases when the sald rollers are brought into engagement with the weldrod carrier 15. This movement,

however, is not coextensive with the movement of the armature 53, and it follows that in completing this movement, the armature acts with a force which will compress the springs 64. as the rollers complete their upy ward movement. This action will exert a gripping pressure upon the carrier 15, and effect the withdrawal 0f the point of the weldrod from its contact'with the work to be welded. The initial arcuate and further parallel movements of the rollers 39 and is reversed for another operation. The` weight of thefeeding rollers 39 and.40, and their connections, will automatically dlsengage the said rollers from the weldrod.

A covering 76, attached to and Supported by the frame 14, may be used to encase the' feeding devices supported upon the welding head.

In some of the appended claims, as well as'at places in this specification, I refer to the feeding devices as acting upon the weld# rod, but I wish this reference to be understood as applying both to the carrier 15, 1 which is supplied. with a weldrod, and to' the weldrod as well, inasmuch as the'sanie plan of operation is applicable to either arf rangement. When the. weldrod supplied by the welding head is of the continuous type, the retaining devices 27 and 28 will be without function, and no provision of the shoulder 27 and reduced portion 69, with which the carrier 1 5 is provided, will be made in connection with the use of a continuous weldrod. l

The references ini some of' the claims to the work relate to the work which is to be welded, and which, in the embodiment of the invention shown,v is embraced within the weldingcircuit. Y

Modifications of the construction shown may be made without departing from the spirit of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent of the United States, is:

1. In an arc welding apparatus, a pair of weldrod feeding rollers, an electromagnet and connections from the armature thereof to move the feeding rollers into engagement with the weldrod and withdraw the latter from contact with the work to strike a welding arc.

2. In an arc welding apparatus, a pairO of feeding rollers arranged upon opposite sides of the line of travel 'of the weldrod, means for supporting the said rollers for movement in converging arcuate paths, and means for moving the rollers as described to withdraw the weldrod from contact with the work'to strike a welding arc.

3. In an arc welding apparatus, a pair of oppositely arranged weldrod feeding rollers, a oating pivot construction supporting the said rollers, and means for moving the said rollers in converging paths to grasp the weldrod to withdraw the latter from contact with the work and strike a weldingI arc.

4. In an arc welding apparatus, a pair of yieldingly mounted rollers for feeding the weldrod`to the work to be welded in the ratio of the fusion of the'weldrod, in com` bination with means for rotating the said rollers to produce such feeding movement.

5. In an arc welding apparatus, a welding l head, a weldrod carrier guided thereon, a

pair of pivotally mounted rollers adapted to engage' the lcarrier and feed the weldrod to the work-to be welded, stops for arresting the relative approach of the rollers, and means .for relieving the weldrod carrier from the feeding pressure of the said rollers when'a predetermined length of the weldrod has been fused.vr

6. In an arc welding apparatus, a welding head, a weldrod carrier mounted for longitudinal ,movement thereon, and having its diameter reduced for a portion of its length,

apair of feeding rollers having a spring pressed en agement with the said carrier, and stops or limiting the movement of the said rollers toward each other, whereby the feeding rollers cease to grip the carrier when a predetermined amount ofweldrod has been consumed:

, actuating the said rollers to feed the weldrod to the work, and stops to prevent engagement of the feeding rollers with the said carrier -when the reduced portion thereof passes between the feeding rollers.

8. In an arc welding apparatus, a welding head,v a weldrod carrier guided thereon, means for retaining the said carrier in its retracted position, while a weldrod is placed in the carrier, and means for releasing the said retaining means, and for advancing the carrier to bring the'l point of the weldrod into contact with the work.

9. In an arc welding apparatus. a welding head, a fusible metallic weldrod guided thereon, an electromagnet and means posi- 4tioned by the armature thereof for withthereof, and a switch for closing the circuit to energize the said magnet.

l0. In an arc welding apparatus, a welding head, provided with guides for'directing the movement of a metallic weldrod. a pair of feeding rollers supported upon the said head, means for moving the said rollers into engagement with the weldrod and withdraw the latter from contact with the work and strike a welding arc, in combination with means for driving the said rollers to feed the weldrod to` the work in the ratio ofthe fusion of the weldrod.

11. In an are welding apparatus, a welding head, a pair of feeding rollers pivotally supported thereon, an electromagnet for -moving the said rollers bodily into engagement with the weldrod to withdraw it from workto strike a welding arc, and means for rotating the rollers in their retracted osition to feed the weldrod in the ratio o the fusion of the latter. f Y

13. In an arc weldingvapparatus, a pair of pivotally' mounted-rollers adapted to be brought into engagement with a weldrod,

and means for effecting such engagement to move the weldrod in one directiony to establish a' Welding are, in combination Withl means for driving the said rollers to reverse the movementof the Weldrod and feed the latter tothe work in the ratio of the fusion of the Weldrod.

14. In an arc Weldinpr apparatus, a pair of bodily movable feedinpr rollers` means for moving said rollers to Withdraw the metall if' u'eldrod from Vcontact with the Work to strike a welding arc. and other means for actuating the said rollers to feed the Wel l rod to the work in the ratio of the fusion of the Weldrod.

l5. In an arc Welding apparatus, a welding head provided with guiding: means for directingthe Weldrod, devices for Withdrawing the Weldrod to strike an arc between the point of the latter and the Work, in combination With means acting through the withdrawing.,r devices to feed the Weldrod to the Work in the ratio of the: fusion of the weldrod.

16. In an are welding apparatus, a pair of feeding rollers for the Vmetallic Weldrod.

. means to move the said rollers bodily to withdraw the Weldrod to strike a weldingr are. and means'for movingthe said rollers rotatively to feed theV ivelidrod to the Work in the ratio of the fusion of the Weldrod.

17. In an arc Welding apparatus, a Wielding head, a pair of Weldrod feeding rollers pivotally supported thereon, an electromagnet for lifting the said rollers into feedinir engagement With the Weldrod. and means for maintaining such engagement 'during the pnlsation of the current in the magnet.

18. In an are welding apparatus, a. Welding,` head, a. pair of normally separated iveldrod feeding rollers, pivotally supported thereon, an electromagnet and connections from the armature thereof to the said rollers, whereby the latter are moved toward each other to grip ,the Weldrod When the magnet is energized, and means for actuatL ing the said rollers to feed the Weldrod to ,the Work as the Weldrod is fused.

19. In an are Welding apparatus, a pair of weldrod feeding rollers, normally spaced apart from the weldrod, meansV for initially moving the said'rollers into gripping en- `agement with the Weldrod and further moving them to withdraw the Weldrod from contact with'c't'he work'to strike a welding moved bodily by the magnetO toGWithdraX-vv the Weldrod` and means for actuating the saidrollers to feed the Weldrod in the ratio of the fusion of the latter.

21. In an are welding apparatus, a pair of movable feeding rollers, an eleetromagnet in the welding circuit to engage the said rollers with the Weldrod and Withdraw it to strike an arcwhen Contact is made with the Work, in combination With means' including;r the said rollers to reverse the direction of movement of the Weldrod and feed the latter in the ratio of the consumption thereof.

In testimony whereof, I have signed my name at Milwaukee, this 18th day of November, 1920. A i

R. STR-ESAU. 

